Running 35mm armoured overhead

[Dcf]

What about abc type cable or the old fashioned method of type 8 overhead channel iron and insulators at each end?
whatever method you decide the fixings will need to be rock solid at each end

 

[Darkwood]

I think the sheer cost of Ladder, post digging, bare or insulated singles wires overhead method all come with large costs, although burying it would in no doubt increase the CSA requirement you should still cost it up and ask the farmer to do the digging work if he can to keep costs low.

All methods are going to be a pain and a knock in his pocket but if that's the power he needs then he has to accept its going to be expensive.

 

[benji]

RS do a 30mtr catenary kit that seems to carry 130kg ? and the dia. is only 3.0mm ??.Today i was looking at a catenary suspended between poles for street lighting approx 25mtr apart total run about 200mtr cable looked about a 25mm swa ? (i was driving at the time ) very little sag between poles and its been there for years.

 

[shanky887614]

RS do a 30mtr catenary kit that seems to carry 130kg ? and the dia. is only 3.0mm ??.Today i was looking at a catenary suspended between poles for street lighting approx 25mtr apart total run about 200mtr cable looked about a 25mm swa ? (i was driving at the time ) very little sag between poles and its been there for years.

might do it. 100m of 35mm 4c is 240kg so should work.


the problem isnt the cable but the fixings either end.

those supports have cable supports as well to keep them up usually and you will need a concrete base etc for them.

it might be cheaper to find a longer route and use a bigger cable, quick search online and 35mm 4c is £9ish a M

so thats £280 just on cable (30m)

70mm is £13pm = £390 (30m)

i bet the cost of poles and everything else will add upto a lot more than installing a bigger cable and going underground or a longer distance

 

[benji]

Correct but if distance is only 25mtr pole might not be required but the fixing of the catenary at each end needs to be paramount

 

[shanky887614]

Correct but if distance is only 25mtr pole might not be required but the fixing of the catenary at each end needs to be paramount

thats the problem.

how many farmers look after there buildings etc? there among the worst for bodges

 

[Guest77]

RS do a 30mtr catenary kit that seems to carry 130kg ? and the dia. is only 3.0mm ??.Today i was looking at a catenary suspended between poles for street lighting approx 25mtr apart total run about 200mtr cable looked about a 25mm swa ? (i was driving at the time ) very little sag between poles and its been there for years.

An experienced Time served Electrician wouldn't consider it :icon12:

 

[D Skelton]

Catenary is possible, but you'd need to sink two proper telegraph poles, plus counter anchoring. He's gonna need deep pockets!

If you're going overhead, I'd also ditch the SWA and go for HO7RNF.

 

[shanky887614]

An experienced Time served Electrician wouldn't consider it :icon12:

Catenary is possible, but you'd need to sink two proper telegraph poles, plus counter anchoring. He's gonna need deep pockets!

If you're going overhead, I'd also ditch the SWA and go for HO7RNF.

thats the thing it soon gets expensive, one of the biggest reasons the dno goes above surface is its cheaper than burying and making good in certain cases.

if you think about the logistics of it, it makes sence.

 

[D Skelton]

I've suspended 5 core 70mm HO7 over a gap of 20m before, but I was securing the catenery to solid concrete on one side, and a metallic ship hull on the other. It is easily doable, but if you're doing it at height, which I wasn't, it needs to be done properly!

 

[Darkwood]

SWA is not a constant flexing cable designed for suspension, the steel armour can work harden very quickly thus breaking or even the cores so anywhere its subject to wind or repeated movement will effect the structural integrity of the cable. You can get away with it to a certain extent with small cables over small gaps but the larger sizes need support fully along the run.

I fit energy cabling (control and power) to machine wiring looms where the cables are specifically designed to repeatedly move with little structural deteriation or core twisting, its a complex calculation but I can usually tell the customer that a cable I have installed is good for 10million flexes and will last x amount of years, a normal flex can only withstand a few hundred to a thousand flexes of a similar nature before it fails.... its from this angle I would advise you don't use SWA suspended free or to a catinery set-up. If you have ever run cable in when its freezing weather you know how stiff the plastics/pvc become so I wouldn't want the wind swinging any such cable against its anchor points as the sheath would just crack and split.

 

[davesparks]

Go old school on it, insulators and hard drawn singles